Terminals, leads, and other conductors for connection to a PCB or an integrated circuit are well known. These connectors are important because PCBs and other electronic substrates in general do not include external leads for connection to associated electronic devices, but include small conductive areas ("pads") on their surfaces. The convenient addition of leads, etc., to the substrate, usually by soldering, is required for efficient and effective use of a substrate.
In recent years, advanced solder-bearing leads have been designed and patented, many by the present inventor, that include a necessary mass of solder at the point of contact with the conductive area of the substrate. After the lead and substrate are juxtaposed, heating the assembly melts the solder, which later cools to form a solid mechanical and electrical bond between the lead and the conductive area. However, since the solder is temporarily liquid, movement of the leads during soldering, which can lead to misconnection or short-circuits, is a serious concern. Custom designs of solder-bearing leads have tackled this problem for different configurations. When conductive areas are present on the upper and lower surface of the substrate, a C-clip is often used that resiliently grips the substrate and holds it in place while the solder is liquid.
The C-clip design has special requirements where electrical contact is desired with the conductive areas of only one surface of the substrate, such as where a substrate includes both upper and lower conductive pads, but only contact with the pads of one surface is desired. Also, a substrate may have only upper conductive pads or lower conductive pads, but it is not desired to have a conductive lead conductively engaging the opposite surface.
There is also a need in the electronic industry for simple and reliable arrangements enabling a manufacturer to test the circuits of substrates to determine whether quality is satisfactory before permanently interconnecting them in more complicated circuits. In many instances during testing of substrates having circuits on more than one surface, it is important to test the circuits on only one surface and insulate them from the other surface.
A variant of the C-clip useful in these situations is disclosed in the present inventor's U.S. Pat. No. 4,780,098. In the lead of this patent, one arm of the C is solder-bearing, while the other arm holds a plastic rod. The rod may extend laterally to adjacent leads, allowing several leads to be held together without a conductive carrier strip. When inserted onto the edge of a substrate, each solder-bearing arm abuts a conductive area on one surface, while the non-conductive rod abuts the opposite surface. In such devices the rod must be secured to the lead, to avoid rotation of the leads with respect to the rod.